Dual gauge
Encyclopedia




A dual-gauge or mixed-gauge railway has railway track
Rail tracks
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...

 that allows trains of different gauges to use the same track. Generally, a dual-gauge railway consists of three rails, rather than the standard two rails. The two outer rails give the wider gauge, while one of the outer rails and the inner rail give a narrower gauge - one of the three rails is common to all traffic. This configuration is not to be confused with the electric third rail
Third rail
A third rail is a method of providing electric power to a railway train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track. It is used typically in a mass transit or rapid transit system, which has alignments in its own corridors, fully or almost...

.

Reasoning

In railways, the most important specification is that of gauge
Rail gauge
Track gauge or rail gauge is the distance between the inner sides of the heads of the two load bearing rails that make up a single railway line. Sixty percent of the world's railways use a standard gauge of . Wider gauges are called broad gauge; smaller gauges, narrow gauge. Break-of-gauge refers...

, the distance between the inner surfaces of the heads of the travel rails (see diagram above). Both track
Rail tracks
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...

 and wheels bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...

s must be built to the same gauge; unless the two fit together within a tolerance of 13 mm (0.511811023622047 in) on the track, the train will either fall off the track or it will be impossible to go through switches or cross overs. For instance, the Hong Kong MTR -gauge EMU's may run on KCR -gauge rails, with a locomotive or a KCR EMU pulling due to different electrify voltages. A problem arises when different gauges meet one another, a situation known as a break of gauge
Break-of-gauge
With railways, a break-of-gauge occurs where a line of one gauge meets a line of a different gauge. Trains and rolling stock cannot run through without some form of conversion between gauges, and freight and passengers must otherwise be transloaded...

. Either the track or the train must be built to handle different gauges, or passengers and freight must be taken off one train and loaded on to the next.

In allowing railway tracks of different gauges to share the same alignment, costs can be reduced, especially where there are bridges and tunnels. Dual gauge can replace two separate tracks, having two rails each, with one track with three rails. This allows one rail fewer for the stretch of the dual gauge line, but there are complications and costs that may offset the savings.

One issue is points
Railroad switch
A railroad switch, turnout or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction....

 (US: switches
Railroad switch
A railroad switch, turnout or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction....

). Complicated arrangements are necessary to ensure traffic of both gauges can safely utilise points. Signalling may also be complicated somewhat, as all three rails must be connected to track circuit
Track circuit
A track circuit is a simple electrical device used to detect the absence of a train on rail tracks, used to inform signallers and control relevant signals.- Principles and operation :...

s or mechanical interlocking arrangements. Mixed gauge is simpler to signal with electric signals than with mechanical signals. Since rails wear very slowly, the extra tonnage on the common rail is generally not a problem.

Dual-gauge turnouts will be complicated, expensive, and suitable for low speeds only.

Configuration

For dual-gauge track to be achievable using three rails, the difference between the gauges needs to be at least as wide as the foot of the rail, otherwise there is no room for the rail fastening hardware (spikes, clips, and the like). Thus standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

  and Indian gauge
Indian gauge
Indian gauge is a track gauge commonly used in India, Pakistan, Bangladesh, Sri Lanka, Argentina and Chile. It is also the gauge that is used on BART , in northern California.- Scotland :...

  can be dual gauged without problem, as are and (Cape gauge
Cape gauge
Cape gauge is a track gauge of between the inside of the rail heads and is classified as narrow gauge. It has installations of around .The gauge was first used by Norwegian engineer Carl Abraham Pihl and the first line was opened in 1862.- Nomenclature :...

), or and , while and (Irish gauge
Irish gauge
Irish gauge railways use a track gauge of . It is used in* Ireland * Australia where it is also known as Victorian Broad Gauge* Brazil where it is also known as Bitola larga no Brasil....

) can also be dual-gauged, albeit with lighter narrow footed rails, as in Victoria, Australia. On the other hand, metre gauge
Metre gauge
Metre gauge refers to narrow gauge railways and tramways with a track gauge of . In some African, American and Asian countries it is the main gauge. In Europe it has been used for local railways in France, Germany, and Belgium, most of which were closed down in mid 20th century. Only in Switzerland...

  and cape gauge
Cape gauge
Cape gauge is a track gauge of between the inside of the rail heads and is classified as narrow gauge. It has installations of around .The gauge was first used by Norwegian engineer Carl Abraham Pihl and the first line was opened in 1862.- Nomenclature :...

  as in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, or and , as in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, are too close to be combined into three-rail dual gauge, as are and , or and , as in Afghanistan
Rail transport in Afghanistan
Railways were planned in Afghanistan since the 19th century but never completed due to the Great Game between the Russian and British empires followed by the Soviets and the Americans. At least one rail track was built in the capital of Kabul during the 1920s but was dismantled as Afghan leaders...

, Central Asia, northern-, central- and eastern Europe, North America, Iran, and China. This last combination is of particular historical interest, as it was of strategic significance during World War II.

If three-rail dual gauge is impossible (e.g. between and ), four-rail dual gauge has to be used.

Gauge conversion

The complications and difficulties outlined show how important it is to ensure that railway gauges are standardised in the first place, if at all possible. If a railway operator seeks to convert from one gauge to another, then it helps if a dual-gauge intermediate step can be done (this has often been practised in the past).

If the gauge is to be reduced, then the sleepers can continue to protrude from the side of the rails. If the gauge is to be increased, then the sleepers used for narrow gauge may be too short, and some at least of these 'short' sleepers will have to be replaced with longer ones. Alternatively the rails may be too light for the loads imposed by broader-gauge railcars. Such potential problems can rule out dual-gauge as a feasible option. Another issue is affixing the rails to the sleepers (spikes, nails or bolts are used). If existing sleepers are wooden, extra holes can be drilled without problems. If the existing sleepers are concrete, then drilling extra holes is impractical, and the whole sleeper has to be replaced, unless extra boltholes are already allowed for.

The embankment could need widening too. It is possible that viaducts and tunnels are too narrow and too low. This could cost a lot and need the closing of the line for a year or two.

During the conversion of the Melbourne-Adelaide railway in Australia from to , dual gauge with heavy rails was not possible as the rail footings were too wide. A special gauge-convertible sleeper with a reversible chair for the Pandrol clip allowed a two-week conversion process.
In the Adelaide metropolitan area, broad-gauge timber sleepers are being replaced with gauge-convertible concrete sleepers. On June 5, 2008, the South Australian Government announced that the Metropolitan Network would be converted to standard gauge (1435 mm) in 2012.

Dual-gauge lines in Java were regauged from to (Cape gauge
Cape gauge
Cape gauge is a track gauge of between the inside of the rail heads and is classified as narrow gauge. It has installations of around .The gauge was first used by Norwegian engineer Carl Abraham Pihl and the first line was opened in 1862.- Nomenclature :...

) during the Japanese administration in 1942-1943. Regauging occurred only on the relatively short Brumbung-Kedungjati-Gundih main line and the Kedungjati-Ambarawa
Ambarawa
Ambarawa is a market town located between Semarang and Salatiga in Central Java, Indonesia.Ambarawa was an important connecting rail link providing a cog railway connecting through Central Java as far as Yogyakarta via Magelang. The Semarang-Ambarawa-Magelang line was fully operational until 1977...

 branch line, as the rest of the line was already dual-gauge (some only recently dual-gauged).

Proposed or current gauge conversions

  • Australia - the new port of Oakajee was previously to be served by separate narrow gauge
    Narrow gauge
    A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...

     and standard gauge
    Standard gauge
    The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

     lines, but Westnet
    Westnet
    Westnet is a Perth-based Australian telecommunications company providing broadband ADSL, broadband ADSL2+, satellite broadband, dialup Internet, telephony and web-hosting services to homes and businesses across Australia.See also Internet in Australia...

    , the track authority, has proposed a common network with a significant length of double track
    Double track
    A double track railway usually involves running one track in each direction, compared to a single track railway where trains in both directions share the same track.- Overview :...

     dual gauge, which has greater flexibility.
  • Australia - South Australia plans to convert its suburban (broad gauge) network to (standard gauge), in 2012, when it is proposed that electrification will be completed. The Outer Harbour Line
    Outer Harbor railway line, Adelaide
    The Outer Harbor Railway Line in Adelaide, South Australia runs from Adelaide Railway Station. It includes many suburban railway stations, and shares part of its run with the Grange line.-History:...

     and Belair Line
    Belair railway line, Adelaide
    The Belair railway line is a suburban rail commuter route within the City of Adelaide, South Australia, that runs from the Adelaide Railway Station to Belair in the Adelaide Hills.-History:...

    s have already been rebuilt with gauge convertible sleepers, whilst resleepering of the Gawler Central line  commenced in 2010. The Noarlunga Line
    Noarlunga Centre railway line, Adelaide
    The Noarlunga Centre railway line is a suburban commuter line in the city of Adelaide, South Australia.-History:Before the extension of the line to Noarlunga Centre line in 1978, the Willunga line ran from Hallett Cove station on a different route through Reynella, Morphett Vale and Hackham to...

     Gawler Central line will commence once the Gawler line is completed.
  • India, Project Unigauge
    Project Unigauge
    Project Unigauge is an ongoing exercise by Indian Railways to standardise most of the rail gauges in India at 1676 mm broad gauge....

     conversion of much of three different narrow gauges to Indian broad gauge.
  • Russia - the railways of Sakhalin Island  are to be converted from (Cape gauge
    Cape gauge
    Cape gauge is a track gauge of between the inside of the rail heads and is classified as narrow gauge. It has installations of around .The gauge was first used by Norwegian engineer Carl Abraham Pihl and the first line was opened in 1862.- Nomenclature :...

    ) to (Russian gauge
    Russian gauge
    In railway terminology, Russian gauge refers to railway track with a gauge between 1,520 mm and . In a narrow sense as defined by Russian Railways it refers to gauge....

    ). As the conversion is going to be done in sections, the conversion plans provide for first laying the third (outer) rail, making rail lines usable by both Japanese- and Russian-gauge trains. Once the railways throughout the island have been converted to the Russian gauge (by 2012), the inner rail will be removed.

  • Spain is building dual gauge track to allow access to high speed trains and freight trains from Europe.

  • Brazil is proposing to build dual gauge gauge to connect ports in the north east.

  • Alaska and British Columbia are proposing dual gauge track so that a narrow gauge tourist train and standard gauge ore trains can share the right of way.

  • Tanzania is the subject of a proposal by Dr. Maua Daftari
    Maua Abeid Daftari
    Maua Abeid Daftari is a Member of Parliament in the National Assembly of Tanzania.- Appointments :* Deputy Minister for Infrastructure Development in 2007. As Deputy Minister she made a proposal to convert the gauge of Tanzania Railways Central line from narrow gauge to standard gauge.- Source :* ...

    . The first step would be to install dual gauge as part of an upgrade in heavier rail.

  • Kenya, Uganda and south Sudan: on 12 October 2004, a proposal was announced to develop an electrified rail link connecting Kenya, Uganda and south Sudan. Even though Kenya and Uganda use 1000 mm gauge and Sudan uses 1067 mm, the new project was proposing to use standard gauge (1435 mm). Fortunately, all three gauges can be supported by the same sleepers, as described above.

Americas

In Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...

 the Los Angeles Railway
Los Angeles Railway
The Los Angeles Railway was a system of streetcars that operated in central Los Angeles, California and the immediate surrounding neighborhoods between from 1901 and 1963. Except for two short funicular railways it operated on tracks...

 and the Pacific Electric Railway
Pacific Electric Railway
The Pacific Electric Railway , also known as the Red Car system, was a mass transit system in Southern California using streetcars, light rail, and buses...

 (both defunct) ran on dual gauge track on some downtown streets.

Asia

In Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, dual gauge is used when standard gauge Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...

 (Bullet Train) lines joins the narrow-gauge system, which is the national standard. For example, part of the Ōu line became part of the Akita Shinkansen
Akita Shinkansen
The is a Mini-shinkansen high-speed rail line in Japan. Serving the Kantō and Tōhoku Regions of the country, it links Tokyo and Akita in Akita prefecture with direct service. From Tokyo to Morioka in Iwate prefecture, it operates on the Tōhoku Shinkansen tracks. From there to Ōmagari, it uses the...

 and was upgraded to dual gauge.

In Dutch East Indies
Dutch East Indies
The Dutch East Indies was a Dutch colony that became modern Indonesia following World War II. It was formed from the nationalised colonies of the Dutch East India Company, which came under the administration of the Netherlands government in 1800....

 (later Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

), dual-gauge track was installed in 1899 between Yogyakarta
Yogyakarta (city)
Yogyakarta is a city in the Yogyakarta Special Region, Indonesia. It is renowned as a centre of classical Javanese fine art and culture such as batik, ballet, drama, music, poetry, and puppet shows. Yogyakarta was the Indonesian capital during the Indonesian National Revolution from 1945 to...

 and Solo
Surakarta
Surakarta, also called Solo or Sala, is a city in Central Java, Indonesia of more than 520,061 people with a population density of 11,811.5 people/km2. The 44 km2 city adjoins Karanganyar Regency and Boyolali Regency to the north, Karanganyar Regency and Sukoharjo Regency to the east and...

. The track was owned by the Nederlandsch-Indische Spoorweg Maatschappij, a private company, which built the gauge line in 1867. The third rail was installed to allow passengers and goods traveling over the gauge Staatsspoorweg (State Railway) a direct connection without requiring transfer at both cities. Later, a separate pair of tracks were installed at the government's cost to allow greater capacity and higher speeds.

In 1940 a third rail was installed between Solo and Gundih on the line to Semarang
Semarang
- Economy :The western part of the city is home to many industrial parks and factories. The port of Semarang is located on the north coast and it is the main shipping port for the province of Central Java. Many small manufacturers are located in Semarang, producing goods such as textiles,...

, allowing gauge trains to travel between Semarang, Solo and Yogyakarta (via Gambringan, on the line to Surabaya
Surabaya
Surabaya is Indonesia's second-largest city with a population of over 2.7 million , and the capital of the province of East Java...

 instead of via Kedungjati on the original line).

A short section of dual-gauge and line existed in North Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...

 on a joint line of the Deli Railway and the Aceh Tramway. This line survived in to the 1970s.

Some sugar mill railways in Java have dual-gauge sections.

In Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

, there is dual gauge ( metre
Metre gauge
Metre gauge refers to narrow gauge railways and tramways with a track gauge of . In some African, American and Asian countries it is the main gauge. In Europe it has been used for local railways in France, Germany, and Belgium, most of which were closed down in mid 20th century. Only in Switzerland...

 and standard
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

) between Hanoi
Hanoi
Hanoi , is the capital of Vietnam and the country's second largest city. Its population in 2009 was estimated at 2.6 million for urban districts, 6.5 million for the metropolitan jurisdiction. From 1010 until 1802, it was the most important political centre of Vietnam...

 and the Chinese border.

Europe

In the Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

, there is dual gauge ( and ) track near Jindřichův Hradec
Jindrichuv Hradec
Jindřichův Hradec is a town in the South Bohemian Region of the Czech Republic. It has approximately 22,700 inhabitants.- History :The first written mention of the town is in 1220. Before that, it was probably a Slavic settlement. At the end of the 12th century more people arrived...

. The two gauges are used by different railway companies.

In Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, the Great Western Railway
Great Western Railway
The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...

 was initially broad gauge
Broad gauge
Broad-gauge railways use a track gauge greater than the standard gauge of .- List :For list see: List of broad gauges, by gauge and country- History :...

, . After the "gauge war", it was decided to regauge the GWR. As the broad gauge was sufficiently dissimilar from standard gauge and used wooden sleepers, dual gauge was easily introduced. The Metropolitan Railway
Metropolitan railway
Metropolitan Railway can refer to:* Metropolitan line, part of the London Underground* Metropolitan Railway, the first underground railway to be built in London...

, now part of the London Underground
London Underground
The London Underground is a rapid transit system serving a large part of Greater London and some parts of Buckinghamshire, Hertfordshire and Essex in England...

 system, started as dual gauge: its present third and fourth rails
Third rail
A third rail is a method of providing electric power to a railway train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track. It is used typically in a mass transit or rapid transit system, which has alignments in its own corridors, fully or almost...

are for electricity supply, not dual gauge. A small section of broad gauge
Broad gauge
Broad-gauge railways use a track gauge greater than the standard gauge of .- List :For list see: List of broad gauges, by gauge and country- History :...

, and standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

  demonstration line exists at the Great Western Society site at Didcot
Didcot
Didcot is a town and civil parish in Oxfordshire about south of Oxford. Until 1974 it was in Berkshire, but was transferred to Oxfordshire in that year, and from Wallingford Rural District to the district of South Oxfordshire...

.

In Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

, dual-gauge track was not used in regauging the Ulster Railway
Ulster Railway
The Ulster Railway was a railway company operating in Ulster, Ireland. The company was incorporated in 1836 and merged with two other railway companies in 1876 to form the Great Northern Railway .-History:...

 (UR). When it regauged
Gauge conversion
In rail transport, gauge conversion is the process of converting a railway from one rail gauge to another, through the alteration of the railway tracks...

 its double-track route from to the new Irish standard of it performed the task in two stages. The Dublin & Drogheda Railway (D&DR) meanwhile was regauging from , too similar to the new gauge to allow dual gauge. Dual gauge was used in Derry
Derry
Derry or Londonderry is the second-biggest city in Northern Ireland and the fourth-biggest city on the island of Ireland. The name Derry is an anglicisation of the Irish name Doire or Doire Cholmcille meaning "oak-wood of Colmcille"...

, by the Port Authority, in an on-street network to transfer goods, on either gauge, between the city's four stations (two narrow gauge, two in broad gauge).

In Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, dual-gauge track is used in the Potenza - Avigliano Lucania line, and .

In France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, the Chemin de Fer de la Baie de Somme is dual gauge between Noyelles-sur-Mer and Saint-Valery-sur-Somme, metre gauge laid within standard gauge, thus having four rails.

In Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, some sections of tram track in Brussels
Brussels
Brussels , officially the Brussels Region or Brussels-Capital Region , is the capital of Belgium and the de facto capital of the European Union...

 combined metric gauge for the interurban trams with standard gauge for the urban trams. Since the closure of the former, these have been replaced with standard gauge track.
In Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, the Stuttgart
Stuttgart
Stuttgart is the capital of the state of Baden-Württemberg in southern Germany. The sixth-largest city in Germany, Stuttgart has a population of 600,038 while the metropolitan area has a population of 5.3 million ....

 tram
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

 lines were gauge. In the 1970s it was decided to convert the tram system to a modern Stadtbahn
Stadtbahn
A ' is a tramway or light railway that includes segments built to rapid transit standards, usually as part of a process of conversion to a metro railway, mainly by the building of tunnels in the central city area....

 and regauge
Gauge conversion
In rail transport, gauge conversion is the process of converting a railway from one rail gauge to another, through the alteration of the railway tracks...

 it to standard gauge to increase capacity. Inner-city tunnel
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...

s replacing street-level sections in busy streets were built with a cross-section suitable for standard-gauge cars. After the conversion started in 1981 with the commissioning of the first three class DT-8 Stadtbahn cars, the tunnels and all other sections used by multiple lines were fitted with / dual-gauge track, to allow both old-style trams and new Stadtbahn cars to share those sections while lines were converted one by one over the next decades. In 2006, conversion of line 15 (the last line to be converted) is under way and was completed in 2008, although some sections will retain their dual-gauge track indefinitely as a courtesy to the tram museum of Stuttgart, which will operate old gauge trams on weekends and special occasions.

Also in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, in Krefeld
Krefeld
Krefeld , also known as Crefeld until 1929, is a city in North Rhine-Westphalia, Germany. It is located northwest of Düsseldorf, its centre lying just a few kilometres to the west of the River Rhine; the borough of Uerdingen is situated directly on the Rhine...

 on Ostwall the tram
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

 lines are dual-gauge track, to allow both standard Rheinbahn
Rheinbahn
The Rheinbahn is a public transport provider operating in and around Düsseldorf. Its network consists of 7 Stadtbahn lines as well as 13 tram and 92 bus services and is integrated in the Rhine-Ruhr Stadtbahn network. The total rail network length is...

 U76 Stadtbahn
Stadtbahn
A ' is a tramway or light railway that includes segments built to rapid transit standards, usually as part of a process of conversion to a metro railway, mainly by the building of tunnels in the central city area....

 cars to share this section with Krefeld
Krefeld
Krefeld , also known as Crefeld until 1929, is a city in North Rhine-Westphalia, Germany. It is located northwest of Düsseldorf, its centre lying just a few kilometres to the west of the River Rhine; the borough of Uerdingen is situated directly on the Rhine...

's metre gauge. At the north end of the street at the junction with Rheinstraße, Rheinbahn trams reverse, so the standard gauge ends, while the metre gauge lines continue. The dual-gauge track continues along Oppumer Straße in front of Krefeld Hauptbahnhof (Main Rail Station), where at both ends of this street, the metre and standard tracks diverge.

In Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 dual gauge track ( standard and metric) is used in (Lucerne
Lucerne
Lucerne is a city in north-central Switzerland, in the German-speaking portion of that country. Lucerne is the capital of the Canton of Lucerne and the capital of the district of the same name. With a population of about 76,200 people, Lucerne is the most populous city in Central Switzerland, and...

 and Interlaken
Interlaken
Interlaken is a municipality in the Interlaken-Oberhasli administrative district in the Canton of Bern in Switzerland, a well-known tourist destination in the Bernese Oberland.-History:...

) stations at both ends of the Brünigbahn
Brünigbahn
The Brünigbahn was, until 31 December 2004, the only narrow gauge railway of the Swiss Federal Railways . On 30 June 2004, the Swiss Federal Council empowered the SBB to sell the Brünigbahn to Luzern–Stans–Engelberg-Bahn , and this company was renamed to Zentralbahn.The Brünigbahn encompasses the...

 and on the RhB
RhB
The Rhaetian Railway is a Swiss transport company, owning the largest network of all the private railways in Switzerland. The company operates most of the railways in the Swiss canton of Graubünden as the Swiss federal railway company SBB-CFF-FFS extend only a few kilometres over the cantonal...

 between Chur
Chur
Chur or Coire is the capital of the Swiss canton of Graubünden and lies in the northern part of the canton.-History:The name "chur" derives perhaps from the Celtic kora or koria, meaning "tribe", or from the Latin curia....

 and Domat Ems (see first illustration of this article), among other places.

In Sweden
Rail transport in Sweden
Rail transport in Sweden uses a network of 13,000 km of track, the 20th largest in the world. Construction of the first railway line in Sweden began in 1855. The major operator is the state-owned SJ AB....

 and Finland
Rail transport in Finland
The Finnish railway network consists of a total of 5,919 km of railways built with Russian gauge track. Passenger trains are operated by the private state-owned VR Group. They serve all the major cities and many rural areas, though railway connections are available to fewer places than bus...

, there is 2 km of dual gauge, and , between Haparanda
Haparanda
Haparanda is a locality and the seat of Haparanda Municipality in Norrbotten County, Sweden with 4,778 inhabitants in 2005. It is adjacent to Tornio, Finland...

 and Tornio
Tornio
Tornio is a town and municipality in Lapland, Finland. The municipality covers an area of of which is water. The population density is , with a total population of . It borders to the Swedish municipality of Haparanda...

 across the bridges over the border. At each end of the dual-gauge section there are yards with standard and Finnish gauge areas to allow for trans-shipment. The four-rail method is used because the gauges are close together. The bridge structure
Structure gauge
The structure gauge, also called the minimum clearance outline, is the minimum height and width of tunnels and bridges as well as the minimum height and width of the doors that allow a rail siding access into a warehouse...

 needs to be wider than normal to allow for the offset from the centreline by each gauge. At the Tornio yard is a Rafil gauge changer. Similar arrangements exist on the approach to Kaliningrad, where track penetrates from the Polish border with some dual gauge stretches.

In Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, there is dual gauge in the AVE
AVE
Alta Velocidad Española is a service of high-speed rail in Spain operated by Renfe, the Spanish national railway company, at speeds of up to . The name is literally translated from Spanish as "Spanish High Speed", but also a play on the word , meaning "bird".AVE trains run on a network of...

 line from Zaragoza
Zaragoza
Zaragoza , also called Saragossa in English, is the capital city of the Zaragoza Province and of the autonomous community of Aragon, Spain...

 to Huesca
Huesca
Huesca is a city in north-eastern Spain, within the autonomous community of Aragon. It is also the capital of the Spanish province of the same name and the comarca of Hoya de Huesca....

, usable for both standard gauge high speed trains and Iberian gauge
Iberian gauge
Iberian gauge is the name given to the track gauge most extensively used by the railways of Spain and Portugal: namely ....

 Spanish trains. In 2009, Adif
Adif
Adif, an acronym of Administrador de Infraestructuras Ferroviarias, is a Spanish state-owned company under the responsibility of the Ministry of Public Works and Transport, charged with the management of most of Spain's railway infrastructure, that is the track, signalling and stations...

 called for tenders for the installation of a third rail for standard gauge trains on the 22 km (13.7 mi) between Castellbisbal
Castellbisbal
Castellbisbal is a municipality in the comarca of Vallès Occidental in Catalonia. It is situated on the left bank of the Llobregat river at its confluence with the Rubíriver...

 and the Can Tunis freight terminal in Barcelona
Barcelona
Barcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...

.

Oceania

In Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

 there is a double-track dual-gauge ( & ) main line from East Perth
East Perth, Western Australia
East Perth is an inner suburb of Perth, Western Australia, located next to the Perth CBD.Primarily an industrial area in the early twentieth century, it was the location of the East Perth gas works, East Perth Power Station , the East Perth railway yard, and East Perth engine sheds.A considerable...

 to Northam
Northam, Western Australia
Northam is a town in Western Australia, situated at the confluence of the Avon and Mortlock Rivers, about north-east of Perth in the Avon Valley. At the 2006 census, Northam had a population of 6,009. Northam is the largest town in the Avon region...

, about 120 km. Dual-gauge track is also used from the triangle at Woodbridge
Woodbridge, Western Australia
Woodbridge is a suburb of Perth, Western Australia, located within the City of Swan. Woodbridge was formerly part of Midland and was previously named West Midland...

 to Cockburn
Cockburn, Western Australia
The City of Cockburn is a Local Government Area with City status, located in the southern suburbs of the Western Australian capital city of Perth. It is situated about south of Fremantle and about south of Perth's central business district...

 Junction, then to Kwinana
Kwinana, Western Australia
The Town of Kwinana is a Local Government Area of Western Australia. It covers an area of approximately 118 square kilometres in metropolitan Perth, and lies about 38 km south of Perth's central business district, via the Kwinana Freeway...

 on one branch, and North Fremantle
North Fremantle, Western Australia
North Fremantle is a small suburb of Perth, Western Australia, located within the City of Fremantle. Its postcode is 6159.The suburb is situated on the Swan River, north of the Port of Fremantle...

 on the other.

In Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...

, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, shorter stretches of dual-gauge track ( & ) exist between the rail freight yards
Classification yard
A classification yard or marshalling yard is a railroad yard found at some freight train stations, used to separate railroad cars on to one of several tracks. First the cars are taken to a track, sometimes called a lead or a drill...

 at Acacia Ridge and the Port of Brisbane, for freight trains. A dual-gauge line branches off at Park Road Station
Park Road railway station, Brisbane
Park Road Station is a railway station in Brisbane, Queensland, Australia. It is part of the Queensland Rail City network.It is in a transition precinct between Zone 1 and Zone 2 of the TransLink integrated public transport system....

 to run alongside the electric suburban narrow gauge Citytrain
CityTrain
Citytrain is the brand name of urban, suburban and inter-urban electric passenger railway services in South East Queensland, Australia. Its network, centering in Brisbane, the state capital of Queensland, is approximately in route length...

 line over the Merivale Bridge into Platform 1 at Roma Street Station
Roma Street railway station, Brisbane
Roma Street railway station is a major railway station in the Brisbane central business district, the state capital of Queensland, Australia. It was Brisbane's first railway station, opening in 1876...

. This is used by standard-gauge interstate CountryLink
CountryLink
CountryLink is the operator of passenger rail services in country New South Wales, Australia and into Queensland and Victoria. It is an operating brand of the Rail Corporation New South Wales, a government-owned entity...

 XPT services to Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

.

Double dual gauge

In Australia, the new railway line between Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....

 and Northam
Northam, Western Australia
Northam is a town in Western Australia, situated at the confluence of the Avon and Mortlock Rivers, about north-east of Perth in the Avon Valley. At the 2006 census, Northam had a population of 6,009. Northam is the largest town in the Avon region...

 was being planned in the 1960s. The improved alignment was originally intended to have separate standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

 and narrow gauge
Narrow gauge
A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...

 tracks running parallel, with crossing loops
Passing loop
A passing loop is a place on a single line railway or tramway, often located at a station, where trains or trams in opposing directions can pass each other. Trains/trams in the same direction can also overtake, providing that the signalling arrangement allows it...

 at intervals. However, the capacity of each of these lines would have been poor. By adopting double-track dual-gauge throughout, the line capacity was greatly increased, at only the relatively small extra cost of providing a third rail was needed for dual gauge.

Triple gauge

There have been a few instances of triple-gauge break-of-gauge
Break-of-gauge
With railways, a break-of-gauge occurs where a line of one gauge meets a line of a different gauge. Trains and rolling stock cannot run through without some form of conversion between gauges, and freight and passengers must otherwise be transloaded...

 stations.
Area Gauge 1 Gauge 2 Gauge 3 Note
Port Pirie, South Australia
Port Pirie, South Australia
-Transport:Port Pirie is located off National Highway One. It is serviced by an airport five minutes out of the city.- Railways :The first railways in Port Pirie were of the narrow [3' 6"] gauge....

1938–1970, .
Gladstone, South Australia
Gladstone, South Australia
Gladstone is a small rural town in the Mid North of South Australia in the approach to the lower Flinders Ranges. At the 2006 census, Gladstone had a population of 629....

1968-1980s
Peterborough, South Australia
Peterborough, South Australia
Peterborough is a town in the mid north of South Australia, in wheat country, just off the Barrier Highway. At the 2006 census, Peterborough had a population of 1,689....

1968-1980s some survives in the Steamtown Heritage Rail Centre
Steamtown Heritage Rail Centre
The Steamtown Heritage Rail Centre is a static railway museum based in the former railway workshops located in Peterborough, South Australia....

Latour-de-Carol
Latour-de-Carol
Latour-de-Carol is a commune in the Pyrénées-Orientales department in southern France.-Transport:The village's main claim to fame is as the site of the international railway station, Gare de Latour-de-Carol-Enveitg...

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

still in use
Hendaye
Hendaye
Hendaye is the most south-westerly town and commune in France, lying in the Pyrénées-Atlantiques department and located in the traditional province Lapurdi of the French Basque Country...

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

still in use
Växjö
Växjö
Växjö is a city and the seat of Växjö Municipality, Kronoberg County, Sweden with 64 200 inhabitants in 2010. It is the administrative, cultural and industrial centre of Kronoberg County. Furthermore it is the episcopal see of the Diocese of Växjö. It has a population of about 64 200, out of a...

, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

until at least 1974
Montreux
Montreux
Montreux is a municipality in the district of Riviera-Pays-d'Enhaut in the canton of Vaud in Switzerland.It is located on Lake Geneva at the foot of the Alps and has a population, , of and nearly 90,000 in the agglomeration.- History :...

, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

still in use
Capolago
Capolago
Capolago was a municipality in the district of Mendrisio in the canton of Ticino in Switzerland, but is now part of the municipality of Mendrisio. On 25 November 2007 the municipalities of Arzo, Capolago, Genestrerio, Mendrisio, Rancate and Tremona voted to merge into the municipality of Mendrisio...

, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

the metre gauge line closed in 1950
Volos, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

600 mm gauge closed on 70's, 1000 mm gauge closed on 1998


Because these three triple-gauge examples were yards operating at low speed, light rail could be used to space the rails closely together if required. Main line operation at high speeds is another matter.

The Niagara Falls Suspension Bridge
Niagara Falls Suspension Bridge
The Niagara Falls Suspension Bridge was the world's first working railway suspension bridge. It spanned and stood downstream of Niagara Falls from 1855 to 1897...

 originally carried trains of three different gauges.

The National Railway Museum (Port Adelaide)
National Railway Museum (Port Adelaide)
thumb|Conference dinner being held in the rollingstock pavilionThe National Railway Museum, Port Adelaide, South Australia, is the current site of the Port Dock Station Railway Museum's vast Australian Railway Collection.- History :...

 in Adelaide, Australia has the three main-line gauges and a gauge tourist line.

Accidents on dual-gauge railways

On September 9, 2004, an accident happened on a switch in Jindřichův Hradec
Jindrichuv Hradec
Jindřichův Hradec is a town in the South Bohemian Region of the Czech Republic. It has approximately 22,700 inhabitants.- History :The first written mention of the town is in 1220. Before that, it was probably a Slavic settlement. At the end of the 12th century more people arrived...

, Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

 where a dual-gauge railway bifurcates. A Junák express from Plzeň to Brno
Brno
Brno by population and area is the second largest city in the Czech Republic, the largest Moravian city, and the historical capital city of the Margraviate of Moravia. Brno is the administrative centre of the South Moravian Region where it forms a separate district Brno-City District...

 derailed due to a signalling error. The standard gauge train was switched onto the narrow gauge track. The express train driver was slightly injured.

In Western Australia, the signalling system detects the gauge of the approaching trains and puts the signals to stop if the route is set for the wrong gauge.

Complexity of dual-gauge switches

Dual-gauge turnouts (also known as switches or points), where both gauges have a choice of routes, are quite complicated, with more moving parts than single-gauge turnouts. They impose very low speed limits. If dual-gauge points are operated and detected by electrical circuits, their reliability will be high.

Where two gauges separate (i.e. each gauge has only one route, as in the picture at right), few if any moving parts are needed.

Third-rail was proposed around 1900 as a solution for the break of gauge problems in Australia, but there was a problem with the design of turnouts due to the closeness of standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

 and irish gauge
Irish gauge
Irish gauge railways use a track gauge of . It is used in* Ireland * Australia where it is also known as Victorian Broad Gauge* Brazil where it is also known as Bitola larga no Brasil....

 of only 6.5 inches. After one or two decades on increasing rancour, the dual gauge option was rejected as unacceptable, especially the Brennan dual gauge switch.

However, where the difference between the gauges is large, say 14.5 inches between and , dual gauge is not a problem, as evidenced by 45 years of successful operation in Western Australia.

Opposition

In Australia, after a brief period of support, dual gauge between gauge and gauge came to be vehemently opposed, even with the Brennan switches, mainly because of hazard of the narrow gap between the outer.

For good measure, dual gauge between gauge and gauge was also opposed, even though the gap is much bigger.

Operation and Detection

The separate ends of dual gauge turnouts are easier to arrange if the ends are electrically operated rather than mechanically operated.

Paradox

If the two gauges of a dual gauge turnout are very similar and the difference between them is small, turnouts will have many small pieces that are difficult to support and the turnout will be weak and limited in speed. Paradoxically, the larger the difference the better. The difference between the gauges should as a rule of thumb be 50 mm greater than the width of the base of the rails. The difference between standard and East European/Russian gauge is too narrow.

Gauge splitters

One way of avoiding complicated and weak dual gauge turnouts, provided there is room, is to separate the gauges and then design the yard with single gauge turnouts and dual gauge diamond crossings. Gauge splitters assume that trains have a single gauge. Gauge splitters may be fixed, meaning they have no moving parts and are intended for low speed use, or they be power operated like ordinary turnouts.

Separate gauge

If dual-gauge turnouts are too slow, or too difficult because the gauges are too similar, then an option is to build two separate lines, one of each gauge, side by side. This choice also depends on the amount of traffic. Dual-gauge could continue to be employed at an expensive bridge or tunnel.

Separate lines can at least share signal box
Signal box
On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable...

es, signallers and other major infrastructure.

Examples include:
  • Albury
    Albury, New South Wales
    Albury is a major regional city in New South Wales, Australia, located on the Hume Highway on the northern side of the Murray River. It is located wholly within the boundaries of the City of Albury Local Government Area...

    , New South Wales
    New South Wales
    New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

     to Melbourne
    Melbourne
    Melbourne is the capital and most populous city in the state of Victoria, and the second most populous city in Australia. The Melbourne City Centre is the hub of the greater metropolitan area and the Census statistical division—of which "Melbourne" is the common name. As of June 2009, the greater...

    , Victoria
    Victoria (Australia)
    Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

    , 300 km
    • As the old and original broad gauge
      Broad gauge
      Broad-gauge railways use a track gauge greater than the standard gauge of .- List :For list see: List of broad gauges, by gauge and country- History :...

       track declines in use, it is slated for conversion to standard gauge
      Standard gauge
      The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

      , replacing parallel standard-gauge single track and broad-gauge double track with a double-track standard-gauge line. This will reduce delays on the standard-gauge line at crossing loops.
  • Melbourne
    Melbourne
    Melbourne is the capital and most populous city in the state of Victoria, and the second most populous city in Australia. The Melbourne City Centre is the hub of the greater metropolitan area and the Census statistical division—of which "Melbourne" is the common name. As of June 2009, the greater...

     Victoria, to Geelong, Victoria, 80 km, a single standard-gauge line parallel to double-track broad gauge.
  • Yogyakarta-Solo
    Surakarta
    Surakarta, also called Solo or Sala, is a city in Central Java, Indonesia of more than 520,061 people with a population density of 11,811.5 people/km2. The 44 km2 city adjoins Karanganyar Regency and Boyolali Regency to the north, Karanganyar Regency and Sukoharjo Regency to the east and...

     in Java, Dutch East Indies during pre-WW II days, 58 km. This had a single line parallelling a dual-gauge and line.

  • Australia - in 1960, the Perth
    Perth, Western Australia
    Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....

     to Northam
    Northam, Western Australia
    Northam is a town in Western Australia, situated at the confluence of the Avon and Mortlock Rivers, about north-east of Perth in the Avon Valley. At the 2006 census, Northam had a population of 6,009. Northam is the largest town in the Avon region...

     line was originally to be separate side-by-side narrow gauge
    Narrow gauge
    A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...

     and standard gauge
    Standard gauge
    The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

     lines, but it was realised that line capacity would be much higher if it were built as double dual gauge.
  • The Uzhhorod – Košice broad gauge track will in 2016 be extended 450 km to Austria parallel to a normal gauge railway.

Platforms

Low level platforms are not a problem with dual gauge trains. since carriages are always higher than the platforms.

With third rails and high level platform, one gauge may be too close or too far away, depending on which side the third rail is. In Western Australia, between Midland
Midland
-Places:In Australia:* Midland, Western AustraliaIn Canada:* Midland, OntarioIn Germany:* Mittellandkanal, the Midland CanalIn Ireland:* Midland Region, a region of the Republic of IrelandIn the United States:...

 and Perth Terminal
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....

 Terminal, the problem does not in practice arise, because the stand gauge trains do not stop and the intermediate stations.

Overlapping gauges

Bangladesh is tackling its break of gauge problem by adding a third rail to its broad and narrow gauge lines, so that it becomes a mainly dual-gauge system. The new Jamuna Bridge
Jamuna Bridge
Bangabandhu Bridge, also called the Jamuna Multi-purpose Bridge , is a bridge opened in Bangladesh in June 1998. It connects Bhuapur on the Jamuna River's east bank to Sirajganj on its west bank. It was the 11th longest bridge in the world when constructed in 1998 and currently the 6th longest...

 that links the east and west rail systems is four rail dual gauge so that both gauges use the same centre-line. At some stage Bangladesh may choose one gauge over the other and convert to a single gauge, but there are no immediate plans for this.

Bangladesh's neighbour to the east is also 1000 mm gauge, should the missing link ever be built.

A variation of overlapping gauge is to extend a railway of one gauge into territory that is mainly of another gauge so as to avoid transhipment of specific traffic. For example a 1524 mm gauge line from an iron ore mine in Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

 to a steelworks in Slovakia
Slovakia
The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

, which now may be extended into Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

.

Other methods of handling multiple gauges

Other methods of handling multiple gauges include:
  • Transporter wagon
    Transporter wagon
    A transporter wagon, in railway terminology, is a wagon or railroad car designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge...

    s or transporter trucks, which carry equipment of one gauge on the other's tracks. This can be also done by the trainload. Bridges and tunnels need to be about one metre higher than they would otherwise be.
  • Bogie exchange
    Bogie exchange
    Bogie exchange is a system for operating railway wagons on two or more gauges to overcome difference in the track gauge. To perform a bogie exchange, a car is converted from one gauge to another by removing the chassis containing the wheels and axles of the car, and installing a new chassis with...

     systems, where the railroad car
    Railroad car
    A railroad car or railway vehicle , also known as a bogie in Indian English, is a vehicle on a rail transport system that is used for the carrying of cargo or passengers. Cars can be coupled together into a train and hauled by one or more locomotives...

     is lifted and the trucks/bogies under it are swapped. This system is not suitable for four-wheel wagons.
  • Adjustable gauge equipment (variable gauge axles), in which the wheel gauge can be widened or narrowed.
  • Transshipment
    Transshipment
    Transshipment or Transhipment is the shipment of goods or containers to an intermediate destination, and then from there to yet another destination....

    , where containers
    Containerization
    Containerization is a system of freight transport based on a range of steel intermodal containers...

     or people are transferred from one set of railroad cars to another.

Dual gauge dual voltage

A mini-metro
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...

 in Gijon
Gijón
Gijón , officially Gijón / Xixón, is a coastal industrial city and a municipality in the autonomous community of Asturias in Spain. Early mediaeval texts mention it as "Gigia". It was an important regional Roman city, although the area has been settled since earliest history...

, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 is to be both dual gauge ( and ) and dual voltage (1500 V DC
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

/3000 V DC).

See also

  • Bogie exchange
    Bogie exchange
    Bogie exchange is a system for operating railway wagons on two or more gauges to overcome difference in the track gauge. To perform a bogie exchange, a car is converted from one gauge to another by removing the chassis containing the wheels and axles of the car, and installing a new chassis with...

  • Break-of-gauge
    Break-of-gauge
    With railways, a break-of-gauge occurs where a line of one gauge meets a line of a different gauge. Trains and rolling stock cannot run through without some form of conversion between gauges, and freight and passengers must otherwise be transloaded...

  • Dual Gauge feasibility
  • Gantlet track
    Gantlet track
    Gauntlet track or interlaced track is an arrangement in which railway tracks run parallel on a single track bed and are interlaced such that only one pair of rails may be used at a time. Since this requires only slightly more width than a single track, all four rails can be carried on the same...

  • Gauge conversion in the US

  • History of rail transport by country
  • Rail gauge
    Rail gauge
    Track gauge or rail gauge is the distance between the inner sides of the heads of the two load bearing rails that make up a single railway line. Sixty percent of the world's railways use a standard gauge of . Wider gauges are called broad gauge; smaller gauges, narrow gauge. Break-of-gauge refers...

  • Railroad switch
    Railroad switch
    A railroad switch, turnout or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction....

     (points)
  • Rail terminology
    Rail terminology
    Rail terminology is a form of technical terminology. The difference between the American term railroad and the international term railway is the most obvious difference in rail terminology...


  • Rail transport
    Rail transport
    Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...

  • Rail transport by country
    Rail transport by country
    This page provides an index of articles on Rail transport by country.Other indexes available include:*List of railway companies by country*List of countries by rail transport network size*Rail usage statistics by country...

  • Ramsey Car Transfer Apparatus
    Ramsey Car Transfer Apparatus
    In railroad industry, the Ramsey Car Transfer Apparatus was a proposed device to replace bogies on railroad cars to permit transfer of a train between railroad lines with different gauge....

  • Variable gauge


External links

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